Our studies are directed towards the mechanisms of translation, transcription, assembly and interaction with host cells of RNA containing animal viruses. One virus is an icosahedral virus (poliovirus) with a single-stranded RNA genome of molecular weight 2.6 x 10 to the 6th power daltons and the second virus is an enveloped rhabdovirus, vesicular stomatitis virus (VSV) whose single-stranded RNA genome has a molecular weight of 3.6 x 10 to the 6th power daltons. We are particularly interested in the manner in which large virus specific polypeptide precursors are processed or cleaved in infected cells to produce smaller end-product poliovirus virion proteins, and in the synthesis, structure and assembly of the glycoprotein envelope protein of VSV.